Granular stock vacuum-drier pneumatic lock control



March 16, 1954 R. DUMERMUTH GRANULAR STOCK VACUUM--DRIER PNEUMATICI LOCK CONTROL 4 Sheets-Sheet l INVENTOR! Filed Oct. 23, 1950 March 16, 1954 R. DUMERMUTH GRANULAR STOCK VACUUM-DRIER PNEUMATIC LOCK CONTROL 4 Sheets-Sheet 2 Filed Oct. 23, 1950 @y Qi??? 4 Sheets-Sheet I5 R. DUMERMUTH GRANULAR STOCK VACUUM-DRIER PNEUMATIC LOCK CONTROL March 16, 1954 Filed oct. 2:5, 195o A W W W March 16, 1954 R. DUMERMUTH GRANULAR STOCK VACUUM-DRIER PNEUMATIC LOCK CONTROL 4 shee'ts-sheet 4 Filed Oct. 23, 1950 5y /6 @mw Patented Mar. 16, 195.4

:GRANUILARTSTOCK VACUUM-DRIER v PNEUMA'IIC LOCIK- CONTROL Appliction- .October-"23, 1950, Serial` N o. y191,571

'Clims priprityfapplication Switzerland October 27,1949

*7 Glaims.

In vacuum dryers-locks :in fform of` valves serving for the `passage of f-goo'dsI to ibeitreate'd, such as grain, corn,lrapesee'd,hazelmitsandithe like, have been mechanically "controlled up to the present.

In contrast thereto,theflockslfaccording"tofzny present invention are pneumatically control'led in accordance 4with a: predetermined 'operating-f program, for which purposef there arefsuitablyproe vided pistons acting,asreversingslides an'dcheck valves associated therewith.

Such a pneu-matic control system,L asi compared with a mechanicalz'controlsystem, is fcheaperin manufacture and 'affords a f'more 'reliablel operation.

4An exampleofmyrpresent invention asapplied to a vacuum dryenis showninthe#accompanying,.partly sch'ematical drawings, in which:

Fig. l isa vertical'sectionLtlro'ughnthe'vacuum dryer,

Fig. 2 is anelevation, in'fallargerfscale, Iota dried-goods dischargeS-rriecl'ianis'massociatedfwith the drying chamber,

ifi-ig. 3 is an:elevationi'seenatfrightangles@to thatv shown in Fig.' 2,

Fig. 4 is a plan'viewaofFfigagpartlyi se'ction,

Figs. 5 anldaeisa verticalisectiommaIlarger scale, through 'the vacuum-dryerfl'i'nlet land fa schematical view of parts of aicontrolfvapparatus,

Fig. 6v shows a .vertiealu'sectinthrough the control apparatus,

Fig. '7 shows avdetail-of Figs. offan'd-" ina larger scale, namelyl a heck' valve;l and Fig. 8 shows a Ifurther I-detaiLJalso f inl a larger scale, namelya venting valve.

The dryer comprises a relatively jtall cylindrical jacket'l (shown brokenawayl'infliigll) :in which is disposeda'heatingdevice of "rectangular cross-section. The said device, as known' in the art, comprises a .tube'system ofv 'tubes' 12 "-tvhich are oval in Vcross-section*and through which steam is fed duringfoperatinofthai-dryer. -l'-The jacket I has frustoeconical `-torn'e'tnd bottom por-- tions 3 and l connected '-to f the i inlet and oiitlet respectively. rEhe inlet and voutlet f each Icomprises two superposed flock chambers 1 5, t Vand 8 respectively, v1:tl-'lese' four vvcl'ianibers Ebeing coaxialv with jacket I. AtLthapointsdoftransition from the top .chamber to chamber-YES ai'idfrom thelatter tota chamber :9 iiornied by the Ieonical top portion 3, fa z'con-icalilockffvalve land Il respectivelyis disposed. .The chamber fwh-ich borders thedrying spaee-I'L.-on toppie boundrat the bottom by a frusto-conicalunnel I3 --fwhich is connectedtotheheating system-2- Atthe 1ower.end of Aspace .t2 ltlfieredstdisposedfwa.dis-

2 charge mechanism comprising four'hoppers I4 of which each 'terminatesin a spont'l tov/'hiena closurerocker Itis/associated. The rockers "I6 are-securedin pairs to a common shaft Stand vrocking movement. 'Ihe shaft I 'if shown Jon -the left in Figs.'3 and .fl'has an'extension towhich is secured a telesco'ping rod'2 Iwhichis connected `to a rod 22 of a working piston f disposed in a control cylinder' 23. The spouts I5 extend down- Wardly'into the lock chamber 'I which is'bound bythe lowerfrusto-c'onicalportion Ll. A'conical loclzvalve 2:3 isf disposed intermediary of vchamber l and the lower lock chamber 8. Another conical lock vvalve is provided between the chamber 8 anda bottom hopper 26 which terminates in adischarge spout.

The'lock valves 'I0, 1h24 and25 are pneumatically actuated, as willbe later explained in detail, .as is also the piston provided in the control cylinder-23 for moving -theshaft-pair -I'i which controls the .rockers It. A shutter Elvis also pneumatically actuated and controls van inlet spout 28` associated with i the topmost lock chamber'. The shtterZ'I is 'pivotedon a pin 29 to the spout'28` and connected to the rod 130 of a Workingpiston 32 "(Fig. 5) which isdisposed in a control cylinder 3|. The llatter is pivoted at' 33' to a cover cylinder 3i which in turn is' pivoted at 33 to a cover-3d of lock chamber 5; if desiredthe cover Sllmay be omitted.

The goods to'be treated are fed in any con'- venient way, e. g. mechanically or pneumatically, to the inletspout 28. When'the shutter is'swung awayfromithe mouth ofvspout 2t, the goods are delivered into the lock 'chamber 5. 'With the shutter 2l in 'closing position andthevalve lo in the 'op'enpositiom Athe: goods 'pass fromfcham berl into the chamber' and thencewith lock valvefl .closed and'lock valve Il open-into the chamber 9 'and,'thus, into Sthedrying space I2. The lock valve II 'then isrclosedvagain. 'The goods, havingpassed the'spaoe I2 (which sfille'd with goods at fall times), is fed l through `the hoppers I4 andthe spouts I5 tothe rochers It whence, when the latter are swung away from the spouts I5, the f'goods :dribble 4iiitothelock chamber fl. With thefrockers I6 in-closing'position andthe -chamber 8 having ibeenfevacuated, the-goods 4pass :from vthe chamber `'I into the chambert, byiopening the v.lock `valve 24,' and 3 thence into the hopper 26, the lock Valve 24 having been closed air admitted into the chamber 8 and the valve 25 opened. The dried goods then pass from space 26 to another treatment station, e. g. to a recooler. The opertion described is repeated so long as the lock chamber provided in the inlet path of the dryer, is fed with goods.

The four lock valves I9, 24 and 25 associated with the lock chambers are actuated, as required, by a working piston each, the said pistons being disposed in stationary control cylinders 35-38 respectively.

The control cylinders 35-38, as well as the above mentioned control cylinders 3| and 23, are connected to a control apparatus by two pipes each. The control apparatus is shown in Figs. 5a and '1, and comprises a camshaft 49 having cams 39 fixed thereto. rlfhe shaft 49 is driven through a chain drive 4| from an electric motor 42, suitably via a reducing gear associated with the latter. A bell crank 44 pivoted at 45 and loaded by a spring 43 (Figs. 6, 7) coacts with each cam 39 and, by means of an extension 49, is connected to a pin 41 of a check valve 48 disposed in a cylinder 49 which comprises the valve seat. All the valve cylinders 49, as shown in Fig. 5a are mounted on a common beam 59. Each cylinder 49 through a tube 5| is connected to a fixed cylindrical casing 52 containing a reversing piston 53 loaded by a spring 54 and having a peripheral groove 55 and a stop projection 53. A branch tube 51 from a header 56 opens into each casing 52. The tube 51 also communicates with casing 52 through a bend 58 which contains a point of passage of extreme constriction 93. rIhe header 56 is connected to a compressor or pneumatic means indicated by 55a in Fig. 5a (not shown in detail).

In Fig. 5a eight reversing stations I-VIII are shown, the casing 52 of each of which is connected to a Valve cylinder 49 through a tube 5l. A tube 59 is connected to each casing 52 and communicates with the peripheral groove 55 of the piston 53. When the piston 53 is moved to the right the tube 59 further communicates through bores 8| and 82 in the casing 52 with the atmosphere. From casing 52 of reversing station I a tube 59, G9 extends to the control cylinder 3| (Fig. 5) which through a tube 6| also is connected to the tube 59 issuing from casing 52 of the recontrol cylinder 39 through two additional tubes 64 and 65 is connected to the two tubes 59 of the casings 52 associated with the reversing stations V and VI. The two tubes 59 of the casings 52 associated with the reversing stations VII and VIII communicate with a vent valve 98 (Figs. 5 and 8) through two additional tubes G6 and 61. The valve 68 through a tube 99 is connected to the lock chamber '5, through a tube 19 to a vacuum pump but indicated at 19a in Fig. 5 (not shown in detail) and through a tube 1| communicates with the atmosphere. The vent valve S8, as shown in Fig. 8, is provided with two springloaded valves 12 and 13 of which the former is associated with tube 10, and the latter with tube 1|.

In a manner similar to that of the control cylinders 35 and 36 of the lock valves ||l and I I, the control cylinders 31 and 38 (Fig. l) of the lock valves 24 and 25 are connected through two conduits 14, and 16. 11 to two separate (not shown) control casings 52 of the control apparatus. The lock chamber 8 through a conduit 18 communicates with a separate venting means 98 of the kind described which also through two conduits is connected to two separate control casings 52 of the control apparatus, and which also comprises a conduit leading to the vacuum pump and another conduit leading to the atmosphere. Aside of the control cylinders 35-38 of the lock valves I9, 24 and 25, two conduits denoted by 19 and 89 are associated with the control cylinder 23 which is provided for the discharge device I4. and so on, of the drying space |2, which conduits 19 and 89 are connected to two separate control casings 52 of the control apparatus.

Before taking in operation the dryer compressed airis passed from the compressor through header 56 to the control apparatus. The camshaft 49 is driven through motor 42 via chain drive 4|, whereby the check valves 48 (Fig. '1) disposed in the cylinder 49 are periodically opened and closed through the cams 39 in a given operating sequence. Assuming that the check valve (48) disposed in the cylinder 49 farthest to the left in Fig. 5a is closed, the following operations will take place:

The air owing from header 58 through branch conduit 51 and bend 59 into casing 52 of the reversing station I moves the piston 53 (Fig. 6) rearwardly against the force of spring 54. When the piston has covered a certain distance of its stroke, the annular peripheral groove 55 thereof establishes communication with the conduit 59 issuing from casing 52, whereupon the air is led through conduit 59 and the connected additional conduit 99 to control cylinder 3|, and the shutter 21 of inlet spout 28 is swung into the open position through the piston 32 of cylinder 3|, the valve I9 of lock chamber 5 being in the closed position. The air expelled from control cylinder 3| owing to the movement of piston 32, escapes to the atmosphere through the conduits 6I, 59, connected to the casing 52 of reversing station II and the bores 8| and 82 of the casing 52 the piston 53 of this station has been moved to the right. After the lock chamber has been charged with goods, that check valve 48 is opened through the respective cam 39, which is disposed in the particular cylinder 49 associated with the reversing station I. In the appurtenant casing 52, therefore, the air-pressure is reduced, and its piston 53 is removed by spring 54 to the right into the initial position, thus the upper room of the control cylinder 3| is connected to atmosphere through the conduits 60, 59 and the bores 8|, 82 of the casing 52 of reversing station I. Moreover, the second check valve 48 from left is closed through the respective cam 39 which is disposed in the particular cylinder 49 associated with the reversing station II. Air thus is fed into control cylinder 3| through the respective conduits 59 and 6| and, therefore, the piston 32 in cylinder 3| is moved in such direction that shutter 2l will close the inlet spout 28. The air expelled from control cylinder 3| escapes to the atmosphere as described before. By reason of the fact that the bend 58 connected to conduit 51 has a constricted owaperture 83, the rate of air flowing from conduit 51 through an open check valve is only small and, thus, is not detrimental in any way.

After a certain amount of goods has accumulated on top of lock valve l0 of the upper lock chamber 5, the lock valve I9 is temporarily opened, namely by means of the piston provided in control cylinder 35 lin that air is fed into the 5 latter through the conduits 63 and 62, which takes place through the casings 52 of the reversing stations IV and III respectively. The function of the pistons (54) of these control casings 52 and that of the check valves (48) in the appurtenant cylinders 49 is similar to that of the corresponding elements as described with reference to the reversing stations II and I for the control cylinder 3l. After the lock chamber 5 has been supplied with goods and the lock valve l closed, air is evacuated from chamber S by the said vacuum pump, in order to balance the pressures in chamber 6 and drying chamber I2, as will be explained later. The lock valve il afterwards is temporarily opened, in the same manner as lock valve IB above, from its control cylinder 32 and the two appurtenant casings 52 of the reversing stations VI and V, in order to let the goods pass from lock chamber into chamber S from which they move to the drying space i 2 which remains filled at all times. Below, the goods are in the hoppers i4, spouts l5 and on the rockers iii. The latter temporarily are swung into the open position by the action of the piston in control cylinder 23, likewise via control casings 52 or reversing stations respectively, provided on the control apparatus and having two appurtenant cylinders 49 with check valves. Following the chamber 1, the chamber S is fed with dribbling goods, whence-as will be explained later-air is evacuated by means of the vacuum pump a, Fig. 5, in order to establish balanced pressures in the chambers 8 and l2. The valve 24 then is temporarily opened in order to let pass the goods from lock chamber '2 r1 into chamber 8. Then air is again admitted into the chamber 8 and the goods are conducted to the hopper 2t by temporarily opening the valve 25. The consecutive actuation of the two valves 2d and 25 is done, in a manner analogous to that of the lock valves l0 and Il, through the control cylinders 3l and 38 from the control apparatus via appurtenant control cases 52 and valve cylinders 49.

Before the lock chamber 5 is evacuated, the appurtenant venting means 68 is in the condition shown in Fig. 8, the chamber 6 communieating with the atmosphere through conduit 69, venting means 68 and conduit ll. In order to evacuate the said chamber 6, the control apparatus causes compressed air to flow into the vent means 68 via the conduit 6l whereby the valve 'I3 is urged on to its conical seat and the conduit 69 is shut off from the atmosphere. On the other hand, compressed air may escape from conduit 66 of the vent means to the atmosphere through the appurtenant control casing 52 by opening the check valve 49, whereby the valve 'l2 on account of being spring-loaded, is opened, whereupon air is sucked oi by the vacuum pump through conduit l0 and, therefore, the chamber 6 is evacuated through the conduit 59. After the goods have dribbled into the chamber 9 due to lock valve Il having been temporarily opened, the condition indicated in Fig. 8 is reestablished in the venting means 68, the lock valve Il having been closed. For such purpose, the control apparatus operates to feed compressed air through conduit 66 to venting means 68 to close valve 12, while compressed air escapes from conduit 61 of the venting means 68 through the associated control casing 52 by opening the check valve 49. The valve 13 thus is opened by spring action, whereupon the lock chamber 6 through conduits 69 and 1l is connected to the atmosphere.

i' il In a manner analogous to that described, the lock chamber 8 is temporarily vented through the conduit 'i8 and the venting means connected thereto.

The outlet spouts l5 on the hoppers I4 of the discharge device are vertically adjustable by clamping means, thus permitting to regulate the amount of goods accumulating in the chamber l. The charge for the lock chamber 5 may be regulated in a similar manner in that the inlet spout 28 and its shutter 2l are mounted vertically adjustable on the cover 34 of chamber 5.

The check valves 49 may be opened by electromagnetic means instead of by mechanical means, or by any other exterior force. If desired, the locks may be constituted by elements of another character than by valves of the type described. Furthermore goods other than those capable or" dribbling may enter into consideration for being passed through the locks. Y

The control system disclosed by my present invention may also be applied to devices serving for grain conditioning.

What I claim as new, is:

l. In a granular stock vacuum-dryer pneumatic lock control, a plurality of independently operative lock chambers for the purpose of passing goods therethrough, a valve for closing and opening each loch chamber, a plurality of fixed cylinders, one for each lock chamber, a movable piston in each cylinder acting as a reversing slide, a check valve associated with each piston, each cylinder having a connection running to said valve, pneumatic means for operating each piston and check valve and each loci; valve, and mechanical means for operating said pneumatic means, operative in a predetermined sequence, in order to operate said pistons in said sequence, and open or close said lock.

2. The structure of claim 1, in which the lock chambers are closed or opened by lock chamber valves.

3. The structure of claim l, in which the pistons are moved by compressed air in one direction, and by spring action in the other direction.

4. The structure of claim 1, in which the lock chambers are closed or opened by valves, and vent means are adapted to co-act with the said pistons and lock chamber valves so as to temporarily evacuate some of the lock chambers.

5. The structure of claim 1, in which the lock chambers are closed or opened by valves, and in which two pistons and two check valves are associated with each lock chamber.

6. The structure of claim l, in which vent means are provided, and two pistons and two check valves associated with each vent means.

7. The structure of claim l, in which vent means are provided, and said lock chambers and lock chamber valves and vent means are adapted to co-act with the said pistons and lock chamber valves so as to temporarily vent some of the lock chambers, a vacuum pump, each vent means having two valves which alternately are closed by the action of compressed air and opened by spring force in order to connect the respective lock chamber alternately with said vacuum pump and with the outside atmosphere.

RUDOLF DUMIEIRMUTH.

Name Date Gieseler Feb. 22, 1921 Number 

